Infectious bovine rhinotracheitis is a clinically and economically important disease of cattle and is endemic in cattle populations throughout the world. Infectious bovine rhinotracheitis caused by BHV-1 is associated with a variety of clinical signs and can cause respiratory as well as reproductive disease. Bovine herpes virus type 1 is often associated with the bovine respiratory disease complex and can also predispose animals to secondary bacterial infections. Bovine herpes virus type 1 is spread through nasal secretions, droplets, genital secretions, serum, and fetal fluids. (Wyler R, Engels M, Schwyzer M. Infectious bovine rhinotracheitis/vulvovaginitis (BHV-1); In: Wittman G, ed. Herpes virus disease of cattle, horses and pigs. Developments in veterinary virology. Boston: Kluwer Academic Publishers, 1989; 1-72).
Nonvaccinated pregnant cattle are susceptible to the reproductive effects of BHV-1, and infections can result in abortion rates as high as 25%. These infections can also result in late-term abortions that can occur up to 100 days after infection. (Kahrs R F. Viral disease of cattle. Ames, Iowa: Iowa State University Press, 1981; 135-136.) Vaccination with either an MLV or inactivated vaccine is the most effective way to control the spread of BHV-1. Modified-live virus BHV-1 vaccines are administered parenterally (SC or IM) or IN, whereas inactivated vaccines are administered SC or IM. However, there have been adverse effects associated with MLV BHV-1 vaccines, including abortion in pregnant animals with unknown or questionable vaccine status (McFeely R A, Merritt A M, Stearly E L., Abortion in a dairy herd vaccinated for infectious bovine rhinotracheitis, J Am Vet Med Assoc 1968; 153:657-661; Nietfeld J C, et al., Multiple abortions in a herd of cows vaccinated while pregnant with modified-live infectious bovine rhinotracheitis virus vaccine, in Proceedings. 43rd Annu Meet Am Assoc Vet Lab Diagn 2000; 14; Annual Report, Animal Disease Research and Diagnostic Laboratory Reports. Brookings, S D: South Dakota State University, 2005-2006).
Five BHV-1 reproduction protection studies have been reported in the literature. Four of those studies have tested MLV vaccine efficacy (Saunders J R, Olson S M, Radostits O M., Efficacy of an intramuscular infectious bovine rhinotracheitis vaccine against abortion due to the virus, Can Vet J 1972; 13:273-278; Smith M W, Miller R B, Svoboda I, et al., Efficacy of an intranasal infectious bovine rhinotracheitis vaccine for the prevention of abortion in cattle, Can Vet J 1978; 19:63-71; Cravens R L, Ellsworth M A, Sorensen C D, et al., Efficacy of a temperature-sensitive modified-live bovine Herpes virus type-1 vaccine against abortion and stillbirth in pregnant heifers, J Am Vet Med Assoc 1996; 208:2031-2034; Ficken M D, Ellsworth M A, Tucker C M., Evaluation of the efficacy of a modified-live combination vaccine against abortion caused by virulent bovine Herpes virus type 1 in a one-year duration-of-immunity study, Vet Ther 2006; 7:275-282). Only 1 study with an inactivated vaccine has been reported (Pospisil Z, et al., The efficacy of an inactivated IBR vaccine in the prevention of intra-uterine infection and its use in a disease-control programme. Zentralbl Veterinarmed [B] 1996; 43:15-21; Pospisil Z, et al., Development of a disease control programme based on the use of an inactivated vaccine against infectious bovine rhinotracheitis, Vet Microbiol 1996; 53: 199-206). This study, however, did not examine the effects of vaccination prior to breeding.
Accordingly, additional methods and compositions for controlling the effects of BHV-1 in cattle are desirable. In particular, effective methods and compositions involving an inactivated vaccine are desirable.